Roche's ($RHHBY) lebrikizumab significantly reduced the rate of asthma attacks in patients with a severe form of the disease, according to mid-stage trial results, lighting the way for a Phase III study on the novel, personalized treatment.

The drug, an interleukin-13-blocking antibody, is designed for severe asthma patients who have high levels of the protein periostin. In two Phase IIb studies on sufferers getting little benefit from inhaled corticosteroids, Roche's injected treatment reduced the rate of asthma attacks by an average of 60% in patients with the biomarker, the company said, compared to just 5% in those with low periostin. Interestingly, the high-biomarker group getting the smallest dose--37.5 mg--charted the biggest benefit, with attack rates falling 81%. On the studies' secondary endpoint, improvement in lung function, the high-periostin group jumped 9.1% while the other cohort improved by 2.6%, Roche said.

Roche believes lebrikizumab's promise in high-periostin patients gives the company a shot at rolling out a personalized treatment for the world's roughly 15 million severe asthma sufferers, and, because the protein can be detected with a simple blood test, the once-a-month drug could carve out a sizable market share. With the Phase II results in hand, Roche has already kicked off two late-stage studies on lebrikizumab in severe asthma with plans to file for approval in 2016.

"We conclude based on these recent results that high levels of periostin, a protein that indicates a certain type of asthma, can predict which patients are most likely to benefit from lebrikizumab," Roche Chief Medical Officer Sandra Horning said in a statement. "The study results are encouraging because more effective treatment options are needed for patients with severe uncontrolled asthma."

Lebrikizumab's latest mid-stage study was initially designed to be a Phase III, but a manufacturing issue forced Roche to dial it back to a Phase IIb, the company said. But that delay hasn't soured Roche's hopes for the drug, which CEO Severin Schwan has said could become a blockbuster, and the treatment is a co-star of the Swiss pharma's immunology pipeline alongside Genentech's etrolizumab, an ulcerative colitis therapy now in Phase II.